The ASP .NET Debugging Options in IIS

There are many occasions we need to troubleshoot the web applications which have several technologies tied together. For the ASP .NET hosting we can enable the server-side and client side debugging as shown in the following screenshots. It is accessed from the Your_Web_Site Properties page provided the ASP was installed and running properly. Make sure you disable these settings for the production or real deployment.

The following screenshot shows the debugging options for ASP .NET which are very useful in assisting the troubleshooting tasks during the development stage.

using System.Web;

using System.Threading;

using System.Text.RegularExpressions;

using System;

using System.Web;

using System.Threading;

using System.Text.RegularExpressions;

namespace AsyncModuleCS

{

    /// <summary>

    /// Demonstrates an async module in ASP.NET

    /// </summary>

    public class AsyncModule : IHttpModule

    {

        // static data members

        static int counter = 0;

        static int modCounter = 0;

        const string RedirectLocation = "accessdenied.aspx";

        // instance data members

        int instanceCounter;

        bool isAuthorized;

        HttpContext ctx;

        Regex locationRegex = new Regex(RedirectLocation, RegexOptions.IgnoreCase);

        public void Init(HttpApplication app)

        {

            // register for our async event

            app.AddOnAuthorizeRequestAsync(new BeginEventHandler(ref AsyncBeginHandler),

                new EndEventHandler(ref AsyncEndHandler));

            // add a sync EndRequest handler to explain what happened if access is denied       

            app.EndRequest += new EventHandler(ref OnEndRequest);

            int modCount = Interlocked.Increment(ref modCounter);

            TraceHelper.WriteLine("Initializing the module instance", modCount);

        }

        // Required on this interface

        public void Dispose()

        { }

        public IAsyncResult AsyncBeginHandler(object src, EventArgs e, AsyncCallback cb, object extraData)

        {

            HttpApplication app = (HttpApplication)src;

            // per-request init

            instanceCounter = Interlocked.Increment(ref counter);

            isAuthorized = false;

            ctx = app.Context;

            // let anyone into the access denied page

            Match m = locationRegex.Match(ctx.Request.FilePath);

            // is it something other than accessdenied.aspx? Check authorization...                                  

            if (!m.Success)

            {

                // create service proxy, async result, and callback

                AsyncModuleCS.localhost.Service1 authServ = new AsyncModuleCS.localhost.Service1();

                MyAsyncResult myAr = new MyAsyncResult(cb, authServ, instanceCounter);

                AsyncCallback myCb = new AsyncCallback(ref WebServiceAsyncCallback);

                // start async call

                TraceHelper.WriteLine("Begin the authorization...", instanceCounter);

                authServ.BeginIsAuthorized(ctx.User.Identity.Name, myCb, myAr);

                return myAr;

            }

            else // otherwise, complete synchronously

            {

                isAuthorized = true;

                TraceHelper.WriteLine("Request for accessdenied asp page, skipping...", instanceCounter);

                return new MyAsyncResult(null, null, true, true, null, instanceCounter);

            }

        }

        public void AsyncEndHandler(IAsyncResult ar)

        {

            MyAsyncResult myAr = (MyAsyncResult)ar;

            TraceHelper.WriteLine("End the authorization...", instanceCounter);

            // if this user isn't authorized, then bail out

            if (!isAuthorized)

            {

                ctx.Response.StatusCode = 403;

                ctx.ApplicationInstance.CompleteRequest();

                TraceHelper.WriteLine("Request Rejected!", instanceCounter);

            }

            // clear variables

            ctx = null;

            instanceCounter = -1;

            isAuthorized = false;

            myAr.EndOp(); // Throw if necessary

        }

        public void WebServiceAsyncCallback(IAsyncResult ar)

        {

            MyAsyncResult myAr = (MyAsyncResult)ar.AsyncState;

            AsyncModuleCS.localhost.Service1 authServ = (AsyncModuleCS.localhost.Service1)myAr.AsyncState;

            // get back result

            isAuthorized = authServ.EndIsAuthorized(ar);

            TraceHelper.WriteLine("WebService call completed...", instanceCounter);

            // tell ASP.NET we're done

            int cnt = instanceCounter;

            TraceHelper.WriteLine("Begin notifing ASP.NET...", cnt);

            myAr.Complete(false, isAuthorized, null);

            TraceHelper.WriteLine("End notifing ASP.NET...", cnt);

        }

        public void OnEndRequest(object src, EventArgs E)

        {

            HttpApplication app = (HttpApplication)src;

            // did we block someone?

            if (app.Response.StatusCode == 403)

                app.Response.Redirect(RedirectLocation, false);

        }

    }

}